Apparatus for drawing tubes of multiple wall thickness



APPARATUS FOR DRAWING TUBES OF MULTIPLE WALL T HICKNESS Filed Sept. 27,1940 W were? PEIZ-WSEA/ 2 Sheets-Sheet l Oct. 7, 1941. o. M. DITZEL ETAL,2

APPARATUS FOR DRAWING TUBES ,OF MULTIPLE WALL THICKNESS Filed Sept. 27,1940 2 Sheets-Sheet 2 4/ 4 I Z3 Z2 7 p IIIIIIIII VI/IIIIIIIIIIIIIIIIIIIIIIIIII TMM rlllllllllllllgm -z Q INVENTORS 05cm MAROMEY 0/7254 *u wag?PFT'E'RJEIV Patented Oct. '7, 1941 A FPARATUS FOR DRAWING TUBES FMULTHLEWALL THICKNESS.

Oscar Maroney Ditzel, Rahway, and Victor Petersen, Plainfleld, N. J.,assignors to Phelps Dodge Copper Products Corporation, Dover,

Del., a corporation of Delaware Application September 27, 1940, SerialNo. 358,692 1 Claim. (01.205-7) I This invention: relates to the drawingof tubes of multiple ;wall thickness where the thickened Wallis used asan armor or reinforcement either in places alongthe length of the tubebetween the ends thereoi'so that itmay be bent at those points withoutreducing the gage at the outside of the bend thinner than the gage ofthe straight part, or at one or both ends to withstand flanging orexpanding or at several points in the length of the 'tube to withstandthe wear occasioned by supporting members. Furthermore thisreinforcement may be on the outside or inside diameter of the tube ascircumstances may require.

Many years ago it was proposed to draw tubes over a mandrel havingreduced diameters in places along its length intermediate its ends andthen by withdrawing the mandrel from the tube, those portions of thetube drawn into the reduced portions of the mandrel being thicker thanthe rest of the tube would be forced outwardly thereby forming a tube ofmultiple wall thickness with uniform inside diameter. While that lookedto be perfect on paper it was found that the friction between the tubeand mandrel where the length was over five. feet was so great that itwas impossible to draw the tube off the mandrel without spoiling thetube.

We therefore propose to draw long tubes over a comparatively short plugheld on the end of the usual plug rod co-axial with a die and in fixedrelations thereto with means to withdraw and/or advance the plug withrespect to the die to regulate the wall thickness of the tube beingdrawn and automatically to control the operation of the plug in itsfixed relation to the die so that multiple tubes of identical wallthickness can be made in commercial production.

With this method of drawing, using our improved apparatus, we can drawtubes of maximum commercial lengths as readily as short pieces and wecanrdraw tubes of most any shape, some of which are shown in thedrawings and designated as series A, B. C, D, E, and F.

The foregoing and other features of our in- Y vention will now bedescribed in connection with the accompanying drawings forming part ofthis specification in which we have illustrated our apparatus in itspreferred form after which we shall point out more particularly in theclaim whose features which we believe of our own joint invention.

In the drawings:

Figure 1 is a side view of a draw bench on which our apparatus isassembled, said bench to be newand being provided with the usualreciprocating carriage and die block.

'of the class A and B.

Figure 2 is a sideview of a means for moving the plug rod drawn to asomewhat enlarged scale.

Figure 3 is a detail of our plug rod mounting at right angles to thatshown in Figure 2.

Figure 4 is a top view of that part of our apparatus shown in Figure 2.

Figure 5 is a section through the die and plug showing their relativeposition in drawing tubes Ii provided with the usual carriage I2propelled back and forth on rails i3, said carriage is adapted to gripthe end of the tube It which is in position over the rod i5 andextending through the die block it. As the travel of the carriage is tothe left, as illustrated in Figure 1, the tube is drawn through the dieand receives its shape depending upon the operation of the rod l5 andthe position and shape of the plug 22 as will now be described.

- Mounted in the die block i8 is a die 2| and on the end of the rod I5is a plug 22 which is held in predetermined relations to the die.

. In Figure 5 the plug 22. is tapered with two diameters 23 and 24. Thesmaller diameter 23 is on the end of the plug away from the supportingplug rod l5; by moving this plug to and from the die, relativelythickened portions M of the tube can be formed. This tube may then bedrawn to a shape corresponding to the F series, Figure 7, by simplydrawing a standard plug through the tube and forcing the inwardlyextending thickened portions of the wall 4! outwardly, or it may beproduced in a single operation as shown in Figure 6 when the plug 22 hasa double taper with three diameters 25, 26, 21. This method is thesubject of our former application #291,288 allowed July 9, 1940.

In order to control the movement of these plugs and to hold them infixed relation to the die, we provide a mounting SI for the end of theing the relative position of the die attached to main frame at dd. Thislever $2 is moved by means of air cylinder 55 pivoted at 65 to amounting 57 and connected to source of air pressure operated by solenoidvalves 68, con-' trolled by llmit'switches 69. These switches areoperated by a shoeilfi carried on the carriage l2.

By adjusting the switches 69 on predetermined centers, the air cylinder65 is made to rock the lever 62 which advances or withdraws the plug 22to or from the the H thus maintainand plug during the time when theparticular thickness of the desired tube is being formed and when thewall thickness is to be changed will automatically move the plug to itsproper position and hold it in its new position forming the other wallthickness. Y

In Figure 7 we show some of the tubes with 7 reinforced or armoredwalls. Series A and B may be formed in a single drawing operation when aplug of substantially theshape shown bracketed to the right andmarked-Wis used.

The series C and D may be formed in asingle operation when a plug orsubstantially the shape shown bracketed to the right and marked X isused. Series E may be formed in a single operation when a plug ofsubstantially the shape ilius trated as Y is used. Series F may beformed in changes or variations may be made as may be.

convenient or desirable without departing from the salient features ofour invention and we therefore intend the following claim to cover suchmodifications as naturally fall within the lines of invention. We claim:Apparatus for forming a tube with multiple wall thickness incombination, means for ing a tube through a die, a plug having a reducedcentral portion and tapering gradually to an enlarged end portion oneach end of the plug mounted to be reciprocated'on the end of a plugrod,.means to reciprocate the rod and to hold the plug in fixedrelations to the die, means operable bythemoveme'nt of the drawing meansto control the means to reciprocate the rod.

f OSCAR MARONEY DI'I'ZEL.

VIC'I'OR PETERSEN.

draw- 7

